well ants go to hibernation when the temperature is falling down... they rest there from about october till march. If u keep the temperature about 25 all the year, they wont go to hibernation... just by giving them the right temperature they "know" when to start hibernation. The temperatures outside and the "free nature" should be ur guide in this case.
the ants haven´t been so active cause they were in their hibernation... they need a temperatur about 8-10°C from about october till march.
Well if temperature never dropped below 15°c she probably didn't get hibernation at all. At this time of year 19 would be enough, in summer 25 is fine to. Now it is to hot.
and so now I keep them inside or in a colder place???
keep her where she is now, but dont´t use heat packs and so.
Perhaps it was better if u answer the questions posted here...
On what temperature are you keeping her now ?
but if she was kept warm like the colony that died now